Lunch box



FIG. 1 is a top, front, left side perspective view of a lunch box showing my new design;

FIG. 2 is a perspective view thereof with the top in an open position;

FIG. 3 is a left side elevational view thereof, the opposite side being a mirror image;

FIG. 4 is a front elevational view thereof; and

FIG. 5 is a rear elevational view thereof.

The undisclosed bottom view is a mirror image of the top view. 

The ornamental design for a lunch box, as shown and described. 